Marmaduke m



MARMADUKE M. M. SLATTERY, OF NEW YORK,

PATENT Trice.

N. Y., ASSIGNOR TO THE SLATTERY INCANDESCENT LAMP COMPANY, OF SAMEPLACE.

PROCESS OF TREATING INCANDESCENTS.

SPECIFICATION forming part of Letters Patent No. 269,239, dated December19, 1882,

Application filed March 6, 1882.

(No model.)

cent Lights, of which the following is a full,-

clear, concise, and exact description, such as will enable othersskilled in the art to which my invention appertains to make use of andpractice the same, reference being had to the accompanying drawing.

The drawing represents one form of a carbonizing apparatus which may beused in carbonizing the filaments,and also in carryinginto effect .myprocess of preparing the filaments as they are being carbonized.

The objectof my invention is to prepare filaments for incandescentlights during carbonization of the same, so as to secure an evenresistance throughoutthe filaments contained in the carbonizingapparatus and it consists in usinga good non-volatile hydrocarbon oil,the fumes of which are so rarefied or diluted and applied to thefilaments while they are being.

carbonized as to effectually accomplish the result in the mannerhereinafter described.

In the drawing, A represents a box into which the filaments to becarbonized are placed. In the bottom of this box there is a passagewayor chamber,B, which is open at each end,

which are of a uniform size, and placed be-- tween thin plates of carbonsurfaced with plumbago, it is then sealed so as to be nearly air-tightand placed in a retort. The temperature is then gradually raised, inorder to prevent injury to the filaments being carbonized. One of thebulbs C C contains non-volatile hydrocarbon oil such as pureolive-oil,1inseedoil, sperm-oil, or any other good non-volatilehydrocarbon oil; but the use of olive-oil is preferred. The other bulbcontains nitrogen gas, which is used for the purpose of displacing theoxygen in the box A and rarefying the hydrocarbon fumes therein, ashereinafter explained.

When the box containing the filaments is placed in a retort for thepurpose of carbonizing the filaments, I charge said box several timeswith nitrogen gas, in order to displace the injurious oxygen therein,the nitrogen being admitted from one of the bulbs into the.

chamber B, from whence it passes through the nipples a (6 into thechamber containing the filaments, thereby displacing the oxygen. Whenthe carbonizingbox is raised to a sufficiently high temperature todecompose the hydrocarbon oil, I allow a feed of a few drops at a timeto pass into the chamber B, whereit is converted into fumes, whichascend up through the nipples a a to the box A, where thereby astrengthening process of hydrocarbon deposition takes place upon thefilaments. I also find it necessary during carbonization to occasionallycharge the box with nitrogen gas for the purpose of diluting thehydrocarbon-fumes contained therein, and also to wash out thesemi-decomposed fumes. By this operation I am enabled to obtain acleaner and more dense deposit of the carbonaceous fumes upon thefilaments, for I find that by the use of a suitable rarel'ying agentunder the above circumstances the dark soft hydrocarbon deposition whichoccasionally takes place upon the filaments operated upon is prevented.The process of charging the carbonizing-box A with hydrocarbon oil,varied by occasional charges of nitrogen gas, should be carried on fromthree to six hours. By this means of preparing the filaments in the boxduring carbonization 1 secure ahigh degree of density, hardness, andelectrical conductivity, and at the same time a more even resistance inthe filaments within the box than has ever before been obtained duringcarbonization.

I am aware that carbon conductors have heretofore been cut from sheetsof carbonized wood or paper, and then' treated in the usual manner by acurrent of electricity passed through them while surrounded by anattenuated atmosphere of hydrocarbon vapor. Such treatment, however, isessentially different from my invention, and Ido not claim it; but

What I do claim, and desire to secure by Letters Patent, is-

The process of preparing filaments during carbonization, which consistsin first placing the filaments within a suitable carbonizingbox thenputting the box containing the filaments into a retort, and, when it isslightly heated, charging the same with nitrogen gas, then raising thetemperature, and, when a high degree of heat is obtained, allowing aslow feed of non-volatile hydrocarbon oil to pass into a chamber beneaththe filaments, where it is converted by the action of the heat intofumes, which arise and surround the filaments, then occasionallydiluting these fumes by a charge of nitrogen gas or any suitable agent,and continuing the process from three to six hours, or a suflicientlength of time to obtain a uniform deposit throughout the filaments,substantially as described.

'M'ARMADUKE M. M. SLATTERY.

